{"id":1882,"date":"2019-03-06T10:04:49","date_gmt":"2019-03-06T10:04:49","guid":{"rendered":"https:\/\/blogs.imperial.ac.uk\/imperial-medicine\/?p=1882"},"modified":"2019-09-10T12:06:45","modified_gmt":"2019-09-10T11:06:45","slug":"a-teaspoon-of-salt-away-from-high-blood-pressure","status":"publish","type":"post","link":"https:\/\/blogs.imperial.ac.uk\/imperial-medicine\/2019\/03\/06\/a-teaspoon-of-salt-away-from-high-blood-pressure\/","title":{"rendered":"A teaspoon of salt away from high blood pressure"},"content":{"rendered":"

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This Salt Awareness Week, Dr Queenie Chan puts the salt intake guidelines to the test and looks at the reality of curbing salt intake for better heart health.\u00a0<\/strong><\/p>\n

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Salt and sodium are often used interchangeably, but they\u2019re not exactly the same thing. Sodium is a mineral that occurs naturally in foods or is added during manufacturing or both. Table salt is a combination of sodium and chloride, which was one of the most valuable modes of currency in ancient times. It has been used to preserve food for thousands of years and it is most commonly associated as a form of food seasoning. Salt also plays a role in food processing, providing texture and enhancing colour.<\/p>\n

Can\u2019t survive without it<\/h2>\n

Our body can’t live without some sodium. Sodium is an essential nutrient for maintenance of fluid balance and plasma volume, transmission of nerve impulses, contraction and relaxation of muscle (including the heart and blood vessels) and normal cell function. It doesn’t take much to do this. Typically about 15% of the sodium we consume comes from foods that naturally contain sodium, such as celery, beetroot, milk, meat and shellfish, and some is added when we\u2019re cooking and eating. Overall, 70% of the sodium we eat comes from salt added to processed and pre-packaged foods, restaurant foods and table salt.<\/p>\n

Salt and blood pressure<\/h2>\n

High blood pressure is a major risk factor for many diseases, such as heart failure, stroke and coronary artery disease, affecting more than 1 in 4 adults in the UK<\/a>.\u00a0 Hundreds of studies have looked at the relationship between salt intake and blood pressure. For example, the INTERSALT Study<\/a> involving 10,079 women and men ages 20-59 from 52 population samples in 32 countries, showed significant relationships between sodium and blood pressure, and prevalence of hypertension.\u00a0 This study also reported that four very low salt intake populations had little or no upward slope of blood pressure with age. For example, the Yanomami people of the Amazon rainforest with just 0.5g salt a day. \u00a0In general, research shows that cutting back on salt lowers blood pressure and reduces the chances of having a heart attack or stroke.<\/p>\n

High blood pressure usually produces no symptoms and our body can tolerate it for a long time.\u00a0 How salt affects your blood pressure depends on your genes, your age, and your general health.\u00a0 However, high blood pressure doesn\u2019t just happen to older people; over 2.1 million people under the age of 45 had high blood pressure<\/a> in England in 2015.\u00a0 This means most of us don\u2019t even realise we have it. That\u2019s why it\u2019s important to have regular medical examinations to make sure your blood pressure isn\u2019t creeping up as you grow older.<\/p>\n

Health policies dependent on antihypertensive drugs alone are only partially successful as many people with high blood pressure do not take medication, or take enough, to achieve control. \u00a0Lifestyle modifications also play a part in management and prevention, with experts recommending a diet rich in fruits, vegetables, legumes, nuts, fish, low-fat dairy products \u2013 and low salt intake.<\/p>\n

But how much salt is too much salt?<\/h2>\n

In 2018, our research team published an article reporting that having a healthy diet may not offset the effects of high salt intake<\/a> on blood pressure, which captured the attention of social media globally.<\/p>\n

I practice what I preach. I do not put additional salt in my food, and eat at least five portions of fruits and vegetables each day. The average intake of salt for the UK (data collected in 2014<\/a>) was 8.0 g, so how hard is it to keep my salt intake to less than 6 g per day \u2013 that\u2019s one and 1\/4 teaspoon \u2013 as recommended by Public Health England<\/a> and NICE guidelines<\/a>?\u00a0 Can I do even better and match the ambitious WHO recommendation of 5 g per day<\/a> (1 teaspoon)?<\/p>\n

My daily salt intake<\/h2>\n

Before I left for work, I already had about 20% of my daily allowance, 400 mg of sodium that is 1 gram of salt!<\/p>\n